Coating treatments with various treating agents have conventionally been performed for imparting water repellency, gloss, and luster to the exteriors of vehicles that are used outdoors, such as automobiles and industrial vehicles, for example, painted surfaces of automobiles. For example, known are a coating process of a water repellent agent for the exterior of a vehicle through application of an amino-modified silicone oil emulsion and then over-coating of another emulsion (Patent Literature 1), a process of lustering a painted surface of a vehicle through application and drying of a coating agent mainly composed of an amino-modified silicone oil and then over-coating and drying of a lustering agent for a painted surface of a vehicle composed of an aqueous emulsion containing a dimethyl silicone oil and an amino-modified silicone oil (Patent Literature 2), and a process of forming a water-slippable film of silicone on a surface of a base material through application of an amino-modified silicone oil emulsion onto the surface of the base material and then over-coating of an anionic silica microparticle dispersion there onto (Patent Literature 3). In each of these processes, an agent mainly composed of an amino-modified silicone oil is applied onto a base material such as a painted surface of a vehicle, and then another agent is over-coated. These agents have insufficient storage stability and also problematic workability during application.
Furthermore, various coating compositions for providing water repellency and gloss to painted surfaces of vehicles are known. For example, Patent Literature 4 describes a lustering and water repellent composition containing dimethyl polysiloxane, amino-modified dimethyl polysiloxane, an acid in an amount necessary for neut ralizing the amino-modified dimethyl polysiloxane, an alcohol, and water. Patent Literature 5 describes a vehicle-coating agent containing a moisture-curing silicone oligomer, a curing catalyst, and a telechelic silicone oil at predetermined amounts. Examples of the reactive functional group contained in the telechelic silicone oil include a hydroxyl group, carbinol groups (—R5OH, wherein R5 represents an alkylene group), aminoalkyl groups (—R6NH2, wherein R6 represents an alkylene group), and carboxyalkyl groups (—R7COOH, wherein R7 represents an alkylene group). Patent Literature 6 describes a silicone composition for water repellent coating composed of a polydimethylsiloxane having trifunctional hydrolyzable groups at both ends, a partial hydrolysis condensate of alkoxysilane having 1 to 4 hydrolyzable groups, an organic titanium catalyst, an aliphatic hydrocarbon or ester solvent, and an alcohol solvent. Patent Literature 7 describes an emulsified lustering agent, which is an emulsion of predetermined amounts of an amino-modified silicone oil having a specific viscosity at 25° C. and a dimethyl silicone oil dispersed in water and having an average oil droplet diameter adjusted to a predetermined level. Patent Literature 8 describes a water repellent composition composed of a telechelic polyorganosiloxane, a metal alkoxide curing catalyst, and an alcohol-based solvent. Patent Literature 9 describes a surface-protective water repellent agent containing a moisture-curing liquid silicone oligomer, a curing catalyst, a modified linear polydimethylsiloxane containing silanol groups at both ends, and a specific volatile solvent at predetermined amounts. Patent Literature 10 describes a water repellency treating agent composed of silicone including amino-modified silicone, a water-soluble organic solvent such as alcohol, and a silicone emulsion emulsified with a surfactant. The water repellency treating agent eliminates the need of surface treatment and other steps that have been conventionally performed and shows satisfactory water repellency even in direct application of the agent alone onto a base material. These agents are each a one-component water repellency treating agent. Agents containing surfactants or acids, however, exhibit insufficient adhesiveness to coating films, water repellency, and gloss.